function Person(first, last) {
    this.firstName = first;
    this.lastName = last;
    this.fullName = function() {
        return this.firstName + " " + this.lastName;
    };
};

const person1 = new Person("Will", "Smith");
const person2 = new Person("Ryan", "Gosling");

console.log(person1.fullName()); // Will Smith
console.log(person2.fullName()); // Ryan Gosling